Cutoff mechanism for bag machines



April 29, 1941. How

CUTOFF MECHANISM FOR BAG MACHINES Filed May 23, 1940 3 Sheets-Sheet 1 INVENTOR W/QLTEE BOG/l0 ATTORNEY April 29,1941. BOCHOW 2,239,874

CUTOFF' MECHANISM FOR BAG MACHINES NVENTOR #4.!72-7? 506/6 0 ATTORNEY.

April 29, 1941. w. BOCJHOW cuToFF MECHANISM FOR me MACHINES Filed May 23, 1940 5 Sheets-Sheet 3 iNVENTOR 14494 725%? 50c Haw ATTORNEY Patented Apr. 2 9, 1941 CUTOFF MECHANISM FOR BAG MACHINES Walter Bocliow, Brooklyn, N. Y., assignor to Equitable Pipe! Bag C0. Inc-,

Long Island City,

N. Y., a corporation of New York 1 Application May 23, 1940, Serial No. 336,695

'iClalms.

The present invention relates to bag machines in which a web of paper is folded over a former to form a bag tube from which successive bag sections are severed in a continuous operation. It is more particularly directed to the severing means in a machine of this character.

In bag machines in commercial use, the severing of the tube walls has usually been accomplished by providing a former with serrated teeth at its edge and providing a lip knife situated above the former and the walls of the tube have been severed against the teeth of the former and the teeth of the lip knife. The resulting bag has serrations along the top of the closing lip or flap and serrations along the top of one. bag wall. These serrations are objectionable in that they do not give a good appearance to the bag and furthermore when the bag is made of some types of bag material, such for instance, as regenerated cellulose sheeting, known commercially as "Cellophane, the serrations frequently permit the initiation of a tear, particularly in materials of this type.

One of the objects of the present invention is to produce a better appearing bag by reason of the fact that the severing of the bag walls is produced in such a manner that a smooth out results.

Another object is to render the machine less noisy by doing away with the usual striker bar mechanism.

A still further object is the production of a smooth out paper bag with less noisy operation but without reducing the high speed with which bags of this character may be produced.

In accomplishing the above objects, one of the features of the invention relates to provision of means whereby the folded web is severed at the forward edge of the former, one wall being severed in advance of the other but both being severed by contact with the edge of the former.

A further feature of the invention relates to the provision of means whereby the severing of the bag walls is performed by a shearing action thereby producing an easier cut-off and resulting in a bag having, smooth edges at the top of one bag wall and at the edge of the closing flap.

Further features of the invention whereby the several objects are attained will become apparent from the following detailed description and claims when taken in connection with the accompanying drawings, in which:

Figure 1 is a central longitudinal section showing the invention applied to a bag machine of known construction and showing so much of the old elements as are necessary to an understanding of the present invention;

Figure 2 is an enlarged sectional view of those parts shown in Figure l which are concerned with the severing mechanism;

Figure 3 is a similar section of some of these parlts in a diflerent position and on a still larger sca e;

Figure 4 is a section on the line |4 of Figure 2; v

Figure 5 is a section on the line 5-5 of Figure Figure 6 is a diagrammatic view showing the manner in which the web is folded to form a bag tube and showing the slits which determine the side edges of the closing flap in the finished bag;

Figure 7 is a fragmentary sectional view showing the position of the parts for cutting off the lower tube wall;

Figure 81s a view similar to Figure '7 but showing a modification;

Figure 9 is a further modification of the same mechanism; and

Figure 10 is a finished bag.

The type of bag adapted to be produced by the machine of the present invention is of the general type shown and described in the patent to George W. Poppe, 1,798,168 March 31, 1931'. According to this patent, preliminary cuts are made in a web of paper which cuts determine the side edges of the closing flap of the finished bag. The web so cut is then passed under the former and the free edges are folded over onto the former to form a bag tube. The overlapped edges are pasted together and the tube is fed through the machine at high speed.

The machine of the present invention operates in a manner similar to the machine disclosed in said patent insofar as making the preliminary cuts in the web is concerned, and the folding of the web into a tube and feeding the tube through the machine. The machine of the present invention differs from the machine of said patent in the manner in which the bag sections are severed from the tube. The drive to the main shaft is also somewhat different.

Referring to Figure 1, there is provided a supporting framework 2 and extending transversely between the side members of this frame work are a number of shafts for operating the various mechanisms all of which are suitably driven from shaft 4. This shaft is provided with the usual sprocket indicated merely by dotted lines in Figure 1 which sprocket drives a sprocket chain 6 which passes arounda sprocket I carried by shaft similar gear ill on shaft ll.

8. This shaft carries a gear 9 meshing with a The latter shaft carries a sprocket l2 which drives a sprocket chain l4 which passes about a sprocket l5 carried by shaft l6. The shaft l6 carries knives: l8 of which one only is shown. These knives may be in the form of dies and are similar in construction and function to the dies 50 shown in Figures 1 and 2 of the aforesaid Poppe patent.

The paper from which the bags are to be made passes from a roll in the form of a web 22, the web being guided by rollers 23 to roller 24 which is preferably of hardened steel. The roller 24 reverses the direction of movement of the web, which after passing the roller 24 engages under the heel 26 of the former 28. As the web passes about the roller 24 it receives a line of paste near one edge which line of paste is supplied by a paste disc 38. During the passage of the web over the roller 24, the knives I8 make cuts indicated at 32, Figure 6. As the web passes under the former, it is folded over onto it and one longitudinal edge is pasted to the other edge to form a bag tube as clearly indicated in Figure 6.

The usual feed rollers 33 are also provided for advancing the web and the folded tube.

The mechanism just described is all found in a bag machine such as that illustrated in the aforesaid Poppe patent.

The present invention is concerned primarily with the cutting of each bag section from the bag tube as the same is fed through the machine.

Instead of the usual striker bar mechanism by Which each successive bag section is severed from the main tube by causing the walls of the tube to engage a former having a serrated edge and a lip knife also having a serrated edge, the construction of the present invention does away with the usual striker bar mechanism and substitultes mechanism which will now be described. This mechanism broadly speaking, includes two revolving and rotatable rollers one of which severs the lower wall of the bag tube at the lower edge of the former and the other roller severs the upper wall of the tube at the upper edge of the former. These rollers are driven in such timed relation that one bag wall is severed after the other so that introducing a bag having a closing flap such as is produced by the method and machine of the said Poppe patent, the bag walls are properly ofi'set. Before describing the particular mechanism whereby these severing rollers are driven, it will first be advantageous to describe the manner in which the shaft 4 is driven since this differs somewhat from the standard bag machine.

Referring to Figure 4, a shaft 3 is driven from a belt engaging a pulley 34. At each end of the shaft outside the frame of the machine are two gears 36, each meshing with an idler 31 which latter engages a gear 38, the latter being secured to the shaft 4 and by which it is rotated.

The severing rollers previously referred to are clearly shown in Figures 2 and 3, the roller for severing the lower wall being indicated at 40 and the roller for severing the upper wall at 42. By mechanism which will later be described, the roller 42 is driven through the gears 38. The lower roller, however, is driven through independent connections from the shaft 3.

The roller 40 is carried by bearings 44, Figure 5 adjustably mounted in extensions 46 which extensions form a part of hubs 48 secured to gears 50. The gears 50 are provided with bushings 5| which bushings rotate on hearing sleeves 52 which are secured to theframework 2 of the machine. Gears are driven from shaft 3, see Figure 4, through a train of mechanism including gears 53 of which only the left hand one is shown in Figure 4. Gears 53 engage idlers 54 which idlers engage gears 50.

The ratio of gearing for driving the gears 50 is such that this gear makes one rotation for each bag section to be cut off.

The forward edge of the former is preferably so shaped that it presents a lower cutting edge 56 and an upper cutting edge 58, as shown in Figure 7. This view shows the position of the parts as the roller 40 has engaged the bag tube against the edge of the former and has severed the lower wall of the tube. The adjustment of the parts is such that the surface of the roller 40 barely touches the lower edge 56 of the former during the severing action.

For severing the upper wall of the bag, mechanism is provided which is actuated through the gears 38, which, as has previously been mentioned, are secured to the shaft 4. There is one of these gears on each side of the machine as clearly shown in Figures 4 and 5. Gears38 mesh with idlers gears 68 and 6|, the latter two gears being also shown in Figures 2 and 3. The idlers 6| mesh with larger gears 62 which latter mesh with still larger gears 63, see also Figure 5.

The roller 42 by which the upper bag tube wall is severed is revolved about the center of a stud shaft 64, Figure 4, to which shaft is secured two gears meshing with gears 63. Secured to the inner ends of the stud shafts 64 are two crank arms 66 to which arms the roller 42 is pivoted from free rotary motion. The roller 42 revolves twice for each bag section and the gear ratio between 63 and 65 is such as to accomplish this result. 1

Due to the fact that the roller 42 makes two revolutions for each bag section cut off, it is desirable during one of these revolutions to prevent the roller 42 from contacting the upper wall of the tube passing over the former. To this end the stud shafts 64 are carried by bearing blocks 68, see Figures 2, 3 and 4. The blocks 68 are slidable in a portion of the framework 2 which is suitably slotted for this purpose. The bearing blocks 68 are urged upwardly by springs 10 and this upward movement is limited by frame blocks 12 secured to the frame by bolts or screws 13. These frame blocks as shown most clearly in Figures 2 and 3, carry cams 14 adapted to beengaged by rollers 15 mounted for rotation on studs 16 secured to the gears 63. During that period of the-rotation of the gears 63 when the rollers 15 are in engagement with the cams 14 the bear ing blocks 68 are depressed against the action of springs Ill and cause the bearing blocks 68 to be moved downwardly to the position whereby the roller 42 will engage the upper edge of the former and sever the upper bag wall at, the instant of such engagement. The position of the parts wherein this action occurs is clearly indicated in Figure 2, where the rollers 15 are in vertical alignment with the center of the shaft carrying the gears 63.

As the bag tube leaves the feed rollers 33, Figure 1, and passes on to the severing mechanism which has just been described, the tube is held in engagement with the rollers 48 and 42 during the severing operation by passing between the enlarged central portion of the shaft 4 as shown in Figure 4 and an upper cylinder 18. This is provided with gears 19 meshing with the gears 34. The central cylindrical portion of the roller I 4 and the cylinder 18 constitute a slip feed whereby the tube is held against the rollers 40 and 42 but these slip feed rollers do not act to retard the tube. Preferably the surface speed of these slip rollers is greater than that of the feed rollers 33 and may be the same as that of the usual bottom folding cylinders to which reference will now be made.

These cylinders are indicated at 88 and 82 and are constructed in the same manner as corresponding cylinders found in the usual bag machine. After the tube has been severed, it is caught between cylinders 88 and 82 and during its passage between said cylinders the bottom of the bag is folded over and pasted. The finished bag passes to a delivery chute 84. The cylinders 88 and 82 are driven as usual through means of an idler 85 meshing with a gear on the lower cylinder, the idler 85 being driven through a gear 10 secured to shaft 4.

Just prior to the severin operation of the tube the same passes between two rollers 86 and 87, Figures 2 and 3, which preferably are freely rotatable on their axes, but are in contact with the tube which is wrapped about the former and which act to support the former against undue vibration during severance of the tube by the rollers 40 and 42. The upper roller 86 is shown as grooved at its central portion to accommodate the seam of the bag tube which seam is indicated at 88, Figure 6.

In Figure 8 a modified form of the invention is shown wherein a groove roller 90 is substituted for the roller 48. In this construction also, the former is provided with the usual teeth 92 and the grooves in the roller 98 fit the teeth in the former. While only one of the rollers 88 is shown it is obvious that the one substituted for the roller 42 would likewise be grooved.

A still further modification is shown in Figure 9 wherein instead of providing the rollers 48 and 42 a cylinder 94 is substituted in each case, which cylinder is not rotatable. It carries a bar 95, however, which is set at a slight angle to the horizontal. When the'stationary cylinder 94 replaces either or both of the rollers 40 or 42 the edge of the former is provided with the cutting edges 56 and 58 shown in Figure 7. With the modification shown in Figure 9, a somewhat better shearing action is obtained. The angle of the bar 95 is exaggerated in Figure 9 to make its structure clear.

The final product resulting from the machine above described is shown in Figure 10 where a finished bag 96 provided with a. closing flap 81 and a bottom fiap 98, is illustrated. It will be noted that the top edge of the flap 911s smooth and does not have the usual serrations which are necessarily formed when a bag is produced 'by the usual mechanism.

Since all of the parts are rotated or revolved in proper timed relation, there is no retarding of the bag tube at any time and hence the speed of operation is as great as in an ordinary bag machine.

What I claim is:

1. In a bag machine, in combination, a former about which a web of paper is folded to form a bag tube, said former having two cutting edges, and means cooperating with said cutting edges for causing one wall of said tube to be severed against one of said cutting edges and the other wall of the tube to be severed against the other cutting edge.

2. In a bag machine, in combination, a former about which a web of paper is folded'to form a bag tube, said former having two cutting edges, and means cooperating with said cutting edges for causing one wall of said tube to be severed against one cutting edge and the other wall subsequently to be severed against the other cutting edge.

3. In a bag machine, in combination, a former about which a web of paper is folded to form a bag tube, said former having upper and lower cutting edges at its forward end, means for feeding the bag tube, and means operated in timed relation with said feeding means and cooperating with the edges of the former to sever the upper and lower walls of said tube against said cutting edges.

4. In a bag machine, in combination, a former about which a web of paper is folded to form a bag tube, said former having upper and lower cutting edges at its forward end, means for feeding the bag tube, and means operated in timed relation with said feeding means for severing the lower wall of said tube against said lower cutting edge and subsequently severing the upper wall of said tube against the upper cutting edge.

5. In a bag machine, in combination, a former about which a web of paper is folded to form a bag tube, said former having upper and'lower cutting edges, means for continually advancing the tube, a roller for severing one wall of the folded tube against the lower edge of the former,

a roller for severing the upper wall of the tube against the upper edge of the former, and means for operating said rollers in timed relation with each other and in timed relation with said feeding mechanism.

6. In a bag machine, in combination, a former about which a web of paper is folded to form. a bag tube, said former having upper. and lower cutting edges, a roller for severing the lower wall of the tube against the lower edge of the former. a roller for severing the upper wall of the tube against the upper wall of the former, means for revolving the upper severing roller at twice the speed of the lower severing roller, and means for moving said upper severing roller out of operative relation with the former during each intermediate revolution.

7. In a bag machine. in combination, a former about which a web of paper is folded to form a bag tube, a roller for severing the lower wall of the bag tube against an edge of the former, a

second roller for severing the upper wall of said WALTER BOCHOW. 

